Kyle Fuller has always been an interesting case study with the Bears. A guy that can never live up to expectations to either end of the spectrum. Regardless of any of his accomplishments or inconsistencies, he's either unreliable, boom or bust, or the consolation prize to "the one that got away." The one, meaning 2017 Defensive Player of the Year, Aaron Donald, who was drafted right before Fuller in the 2014 NFL Draft. Many still think of Fuller as the answer to the trivia question of "who the Bears had to settle for after missing out on a generational defensive player."

For Fuller's sake, that's a football false equivalence of the highest degree. An unjust comparison with Donald that he'll never live up to, nor one that he has to entertain.

Ever since, Fuller - an athletic and hard-nosed cornerback - has been fighting an uphill battle. After exploding onto the scene with four interceptions as a rookie, Fuller struggled the rest of the 2014 season. After settling in well with his now entrenched defensive coordinator Vic Fangio in 2015, he missed the 2016 season with a "Where's Waldo" knee injury that Fangio felt more than comfortable to criticize him for. Finally, after coming through with a complete 16 game season in 2017, there are questions of who the real Fuller is as a player.

Is it the Fuller mired by inconsistency and injury early in his career, merely putting it together after a fifth-year contract option was denied? Or is the 26-year-old Fuller who came in second in the NFL with a career-high 22 pass deflections last year, the real deal?

From Fuller's perspective, he thankfully doesn't have to answer to any of the skepticism. That's because as the two week window to franchise tag him for the Bears opens today, he's done his part. He's put himself in a position to cash in after finishing his rookie deal with Chicago. He's the one that worked to make himself an available player after missing the previous year.

For as much as Fuller's camp will no doubt negotiate hardly with the Bears, the burden of proof is almost completely on general manager Ryan Pace. Ultimately with internal debates aside, the decision to tag Fuller, sign him long term, or let him walk, will fall to Pace and no one else. It's on Pace to show his quiet Rod Tidwell the money.

Given where the Bears sit in the thick of Mitchell Trubisky's rookie contract, and with players such as Akiem Hicks at the tail end of their primes, it'd behoove them to retain their homegrown talent in Fuller at a compromise that works for both sides. The time to win and contend for a championship is now. Losing Fuller and letting him walk sets the organization back.

But these old fashioned Western standoffs can get complicated in the NFL. The leaks in the media will begin of a "source said this and this about Fuller" and "Bears are seeking this from Fuller" as to garner favor in public opinion. None of them will matter until someone signs on the dotted line. Hardball with your own potential free agents is a tricky subject for teams. The Bears can't avoid it any longer with Fuller.

Let's unpack the scenarios and models in play for the Bears and Fuller over the course of the next couple of weeks.

Contract precedents to "pay the man"

If Fuller is offered a long-term deal with the Bears, he'll be pleased to know what's in store. The top or second-best cornerback available in every free agency are almost always relatively overpaid for their services. The position as a whole has teams investing a bevy of money into it, sometimes more than they should.

Fortunately for Fuller, he's widely considered the best or second-best cornerback potentially available next to the Rams' Trumaine Johnson. The opportunity to cash in looks grand for both.

Since the NFL salary cap has steadily risen by an average of $10 million over the past four seasons, it doesn't do any good service to look at the top-paid free agent cornerbacks from a decade ago.

As a rough comparison and estimate of what to expect for a potential Fuller deal, here are the top two contracts given out to cornerbacks over the last four years. And what subsequently happened to each player after signing their deals.

2014:

• Aqib Talib, six years for $57 million with $26 million guaranteed to the Broncos.
• Vontae Davis, re-signs with the Colts for four years, $36 million with $20 million guaranteed.

Four seasons later, both of these corners have already either been cut in the case of Davis this past November. Or stand reason to be on the likely chopping block in Denver in regards to Talib.

Nevertheless, both largely played out most of their contracts and gave the Broncos and Colts respectively what they payed for. Talib especially, as he was the No. 1 cornerback on one of the best defenses of the modern era in the 2015 Super Bowl 50 champion Broncos. Davis wasn't able to finish his last season in Indianapolis healthy, but turned in Fuller-like numbers over the first three years of his deal.

2015:

• Darrelle Revis, five years for $70 million with $39 million guaranteed to the Jets.
• Chris Culliver, four years for $32 million with $16 million guaranteed to the Redskins.

2015 exemplifies NFL teams getting too happy with the trigger finger in offering money to cornerbacks that don't technically warrant it.

Revis, fresh off a No. 1 generational cornerback and one-year mercenary $20 million dollar deal with the Patriots, wasn't going to settle for anything less on the final mega contract of his career. It doesn't lend any credence to the Jets giving a player well past his prime historic guaranteed money, though. A decision they paid for as Revis was a shell of himself in his return to New York before eventually being released last February.

In Culliver's case, he was a No. 2 to No. 3 average cornerback on a San Francisco team absolutely loaded up front defensively. A front that masked his deficiencies. Him being paid handsomely money he wasn't worth is another classic Washington football move. Culliver was suspended the second game of the 2015 season for derogatory racial remarks made back in 2014. He would then tear his ACL and MCL late that November, and not even finish one season with the Redskins leading to a release that off-season.

2016:

• Josh Norman, five years for $75 million with $50 million guaranteed to the Redskins.
• Janoris Jenkins, five years for $62.5 million with $28 million to the Giants

Another classic Washington football move. Norman is by no means a bad player. He's a top-10 cornerback and overall top-tier defensive guy in football. But how smart does it look two years later to give him more than 60 percent guaranteed money on one of the most lucrative deals ever as young corners like Marshon Lattimore and Jalen Ramsey rise up? Not a great deal of foresight. It's not as if he was going to accept less after a breakout 2015 season to be fair.

From Jenkins' case, being the kind of player he is as a non-field tilter wasn't a terrible investment for the Giants. He helped New York stake out a 2015 playoff berth and wasn't awful last year in a lost season for the "G-men". With the reasonable amount of guaranteed money handed out, New York could theoretically cut their losses with Jenkins now for a minimal hit. Seeing as how he's still performing well, the Giants are getting their money's worth.

2017:

• A.J. Bouye, five years for $67.5 million with $26 million guaranteed to the Jaguars
• Stephon Gilmore, five years for $65 million with $40 million guaranteed to the Patriots

The free agency of Ryan Pace's discontent is on display with these two.

Seeing Bouye, the Bears were in heavily on his services and apparently offered him a bigger contract than the one he eventually signed with Jacksonville, according to Bouye himself. Next to Ramsey, Bouye helped form the NFL's top cornerback duo last season. With a comfortable average cap hit and reasonable amount of guaranteed money for Bouye, that fact that may not change for quite awhile. The free agent that got away.

While Gilmore is probably the best deal Pace never made. The Bears were also heavy in on New England's star corner, but there was no way they were going to give Gilmore a little under 66 percent guaranteed money over the course of his deal. Gilmore is a "very good" cornerback, not a special game changer. And one could argue the special guys such as Norman aren't worth their money either.

The win-now Patriots were in position to make that move and it almost paid off with back-to-back Super Bowl titles. The Bears, who'd eventually draft a rookie quarterback in Mitchell Trubisky, were not. It'll be fascinating to see how this Gilmore investment for New England plays out over the next few years.

The long term Tidwell contract

Back to Fuller himself, with the kind of money he'll seek in mind now, the elephant in the room is to whether the Bears can lock him up through the rest of his prime. And whether it can be done without alienating him and hamstringing their own salary cap. A contract that can satisfy both sides to where this isn't an issue moving forward.

For posterity's sake, Fuller's caliber is more in the realm of a Bouye. The Bears aren't likened to give any cornerback the kind of guaranteed money Norman or Gilmore received. Expect eventual figures on a potential contract with the Bears to settle in at a $12.5 million average with close to $30 million guaranteed.

It's going to likely come down to term for most free agent players, as they care more about security towards the twilight of their deal. Guaranteed money is used as a protector for teams to cut their losses, because every player in their prime believes they'll play their deal out in full. Take out your calculator: five years, $62.5 million with $30 million guaranteed sounds right for Fuller in Chicago.

To tag or not to tag, that is the question

If the Bears elect to franchise or transition tag Fuller (you can only use one altogether per off-season, but are free to rescind during the tag window), they're putting off this decision to where it can backfire for them tremendously.

With the franchise tag, if Fuller enjoys another sterling 2018 season, he hits next year's open market with a full head of steam at a price the Bears might not be willing to pay. Or at a price they'll have to pony up much more for. If Chicago exclusive franchise tags Fuller (unlikely), long-term negotiating is done. If the Bears use a non-exclusive tender, Fuller can talk to other teams. Currently, the one-year 2018 franchise tag price barometer - an average of the top-five at your position - sits at approximately $15 million for cornerbacks.

If the Bears transition tag Fuller, that would mean they pay him in the neighborhood of the top-10, not top-five, highest paid corners. It would also open up the door for teams to offer Fuller respective contracts, with the Bears possessing the right to match.

Transition tags, in contrast to their misused franchise cousin, are typically doled out to help teams negotiate with their homegrown talent. That's because after teams begin offering the player a deal, said player gets an idea of what he's worth on the open market and it helps establish a baseline in negotiations. Since there's no risk of losing the player unless so inclined because you can match every offer, it's a nice bubble to deploy.

Now, there's always the danger that someone writes a blank check for Fuller to where the Bears don't match. But if the Bears elect to use the transition, that would mean they're comfortable with what they expect his value would be as a free agent to let him test the waters.

Aside from outright reaching a deal without any loopholes, a transition would be an excellent failsafe to both negotiate with and keep Fuller on for the 2018 season should those negotiations not go as planned.

Bid you adieu

The last worst case, no holds barred, nuclear fallout road is letting Fuller walk and sign with another team in free agency. Doing this would mean the Bears likely pull out the stops for someone such as Johnson, as saving that money in another prime salary cap year doesn't make sense.

The risk that this poses is that Johnson isn't guaranteed to sign with the Bears, while Fuller is still in their control and their building for the time being. A guy such as Johnson, the next best fit and someone many have long advocated to come to Chicago, is also more likely to come at a price the Bears wouldn't be comfortable with. For one, because he doesn't understand their system. For the other, because Johnson is also in the "very good" not star category of cornerbacks.

If Fuller leaves, he'll assuredly be paid handsomely while the Bears look to pick up the pieces with Johnson or in April's draft.

Learn from your past

Many have compared Fuller's pending situation to how Alshon Jeffery's departure last year played out, but that's redundant and inaccurate.

Pace slow played Jeffery and already tagged him in the 2016 off-season after not signing him to a long-term deal in 2014. Fuller missed the 2016 season, didn't have his fifth-year option picked up, and is now instead at the same juncture that Jeffery was two years ago. Correlation does not equal causation with this revisionist's history as most wouldn't have picked that option up for Fuller following not playing a third year.

That doesn't change the fact that the Bears aren't in position to let Fuller walk. And regardless of how you felt about the dealings with Jeffery, there's always the possibility that Pace may have learned from what transpired with him to apply to Fuller. Especially as the Bears bring back Fangio for another three seasons that keeps Fuller up to speed. Defensive has become a clear important factor at Halas Hall, and Fuller is a part of that.

Whether Pace did take any lessons from the past or not, the future of Fuller as one of the Bears' franchise players hangs in the balance. In the words of the late Gene Wilder as Willy Wonka: "The suspense is terrible. I hope it will last."

Robert Zeglinski is the Bears beat writer for The Rock River Times, an editor for Windy City Gridiron, and is a contributor to The Athletic Chicago. You can follow him on Twitter @RobertZeglinski.